1. Field of the Invention
The present invention relates to an electric connection-inspection device in which a plurality of contact terminals are brought into press and contact with electrodes of semiconductor elements or the like as inspection objects to input and output an electric signal thereby inspecting electric features thereof.
2. Description of the Related Art
Many semiconductor elements of LSI are provided on a semiconductor wafer, and they are cut and divided into chips for use with various products to be utilized of electric products. Normally, on the surfaces of these semiconductor chips are arranged with a number of electrodes along the circumferences thereof. In producing the semiconductors described above in volume industrially, a connection-inspection device generally called as a probe card is used in order to inspect their electric features.
This probe card is constituted by a card substrate 1 comprising a resin substrate in which a wiring is buried as shown in FIG. 1, and a contact terminal 2 comprising a metal needle projected obliquely therefrom. The actual inspection is carried out by rubbing an electrode 5 on a semiconductor wafer 4 by contact pressure making use of flexure of the contact terminal 2 to remove an oxide film naturally formed on the surface to attempt an electric contact. Further, also in case where these are inspected, before the elements cut and divided into the chips are actually mounted, there is used a connection-inspection device called a contactor (or a socket) having a number of contact terminals, which is constituted so that the contact terminals are likewise brought into contactor-contact with the elements to enable inspecting electric features. It is noted that also for inspection of electric features of various electronic devices such as a display unit, a connection-inspection device generally called a probe is being used.
With the recent trend of fineness of semiconductor elements, also as a connection element used to perform electric inspection thereof, a fine element has been proposed. For example, in Japanese Patent Laid-Open No. 283280/1995 Publication, there is proposed a probe card in which a contact terminal is formed by making use of a mold for anisotropy etching of silicone with a photolithography technique as a base, a hard plating material is formed therein, and a conductive layer is formed on the uppermost surface. Further, in Japanese Patent Laid-Open No. 159696/1997 Publication, there is also made a proposal in which a photolithography is used to form a wiring part, which is used as a connection terminal.
However, the conventional fine connection-inspection device as described has a disadvantage that since the entirety is originally fine, an extreme end of the contact terminal also becomes fine, strength is low, a breakage caused by abrasion or foreign matter tends to occur, and also durability is low.
On the other hand, for a wiring used in such a device as described, a low electric resistance is required naturally, but the wiring itself becomes fine due to the correspondence to fineness of the above device, that there poses a problem that the electric resistance of the wiring increases conversely. To cope with this, a material, thickness, and forming method of the wiring part are under fixed restriction, which is not preferable. The wiring part is often formed, generally, of gold, nickel, an alloy of copper, etc. However, a freedom in terms of selection of material is narrow due to the above-described electric restriction, and particularly it is difficult to apply material of high strength.
Moreover, even if materials of high strength and low electric resistance could be selected, these materials are so high in internal stress that a fully thick film is difficult to be formed, still failing to sufficiently achieve a function as a connection element.
Furthermore, as a problem in terms different from that mentioned above, there occurs a problem in that with the development of a semiconductor element using a bump such as solder and metal, an electrode element becomes adhered to and coagulated on the extreme end of a contact terminal, resulting in contact failure at the time of connection-inspection. For overcoming this problem, a periodical cleaning operation is necessary, and not only the inspection efficiency lowers but also the durability of the contact terminal is impaired.
It is therefore an object of the present invention, for solving the aforementioned problems, to provide an electric connection-inspection device which overcomes the aforementioned problems at a stroke, which does not impair a freedom of selection of using materials from a viewpoint of restriction in terms of product""s function with the aptitude of electric features of electric resistance and physical properties of internal stress, and restriction in terms of manufacture as to the appropriation or not of employment of a plating method, and which has a fine construction provided with the excellent durability that an electrode element is hard to adhere and coagulate.
The present inventors have earnestly experimented and studied aiming at solving the problems as noted above, and as a result, have accomplished the present invention as industrially advantageous technical solving measures.
The present invention provides an electric connection-inspection device for coming into electrically contact with an object to be inspected to input and output a signal, comprising: a plurality of contact terminals and contact parts positioned at extreme ends of the contact terminals, the contact part comprising a first layer formed from a wiring base-material, a second layer formed on the surface of the first layer and comprising a coating of material having the Young""s modulus higher than that of the wiring base-material and whose specific resistance is 1xc3x9710xe2x88x924 xcexa9cm or less, and a third layer comprising a coating of material having a low coagulating property.
In the electric connection-inspection device constituted as described above, the second layer is preferably formed of a material having the Young""s modulus of 150 GPa or more, its thickness is preferably 3 xcexcm or more, and its material can be tungsten or its alloy.
In the electric connection-inspection device constituted as described above, the material for the third layer can be carbon, carbon containing a metal element, a nitride of metal or carbonitride. Among them, carbon containing a metal element of 0.5 to 50 atom % is preferable. That metal element can be at least one selected out of titanium, vanadium, niobium, zircon, molybdenum, tungsten, tantalum, hafnium, chrome, manganese, iron, cobalt and nickel.
In the electric connection-inspection device constituted as described above, preferably, the contact part is so constituted as to form a projection projected from the contact terminal. The projection can be a truncated pyramid shape.
In the electric connection-inspection device constituted as described above, the device can be constituted merely by the first layer and the second layer.
The electric connection-inspection device according to the present invention can be used as a probe or a probe card, or a socket or a contactor.